1. Field of the Invention
This invention relates generally to efficient operation of a semiconductor supply chain, and more particularly, to providing a work-in-progress (WIP) tracking system and generating a variety of meaningful WIP tracking reports to customers.
2. Description of the Related Art
A typical semiconductor manufacturing process includes multiple phases. For example, a wafer foundry (or fab) begins with raw silicon wafers and fabricates integrated circuits on these wafers. A test vendor may test the integrated circuits and mark the good die on the wafer. An assembly/packaging vendor may dice the wafer into separate die and assemble the good die into various packages with appropriate electrical connections. A final test vendor may perform final testing of the finished packaged part to make sure that the chips are operating according to specification. A shipping vendor may transport the WIP between the different supply chain vendors and finally distribute the finished good parts to their intended destination. Thus, the semiconductor supply chain may include many separate entities, all of which shall be referred to as vendors.
As the semiconductor manufacturing process becomes more complex, companies in this industry are specializing. As a result, customers, such as fabless semiconductor companies and integrated device manufacturers, are using an increasing number of semiconductor supply chain vendors for prototype development or mass production of integrated circuits. In other words, generally speaking, the semiconductor supply chain contains an increasing number of vendors. Thus, it would be beneficial for customers to obtain concise, meaningful reports as to the status of WIP within their supply chains.
However, one characteristic of the semiconductor industry is that vendors in a semiconductor supply chain are often located in different time zones, in different countries, or speak different languages, making person-to-person communications difficult. In addition, manufacturing data and other information provided by the vendors may be in incompatible formats or have other deficiencies such as providing unreliable prediction of product quantity or shipment date. The resulting difficulty in effective communication and information sharing throughout the supply chain can cause significant barriers to generating consistently meaningful WIP tracking reports.
To aid the customer to keep track of the IC manufacturing process on the supply chain, some supply chain vendors send work-in-progress (WIP) updates to customers. For example, typical WIP updates from a foundry vendor contain raw manufacturing data and information pertinent to an order made by the customer. The manufacturing data and information typically are reported on a per-unit basis. For example, if an order is subdivided into lots, the WIP update may specify the number of wafers in each lot, where the lots are in the manufacturing process, the start time for each lot, etc. WIP updates generally are produced regularly (e.g., three times a day) for every lot in production, at every stage of production. The resulting volume of data in the WIP updates is immense.
However, the WIP updates, although they contain an immense amount of very detailed information, are usually meaningless for customers. They fail to give a customer a clear summary of what is most important to him. For example, one important business concern for customers outsourcing IC manufacturing is the on-time completion and delivery of IC products at each phase of the supply chain. An update which summarizes how many packaged and tested IC products can be expected to be delivered on the originally scheduled date would be useful. However, WIP updates generally fail to give this type of information. Instead, the typical WIP update details exactly where each unit of product is in the manufacturing process. The customer would have to perform a sophisticated statistical analysis to convert this raw WIP information to an estimate of on-time expected good parts. As another example, it is also of interest to customers to monitor the progress of IC orders as the WIP moves between supply chain vendors. If delays occur at some stages to some vendors so that the ordered IC products will not be available on time, the customers may choose to subcontract with additional supply chain vendors to reach production goals. Again, typical WIP updates do not directly supply this type of information.
Therefore, what is needed is a system and method to analyze raw WIP data and provide a meaningful and appropriate presentation of WIP analysis results to a customer. For example, converting raw WIP data into the expected good parts currently at each major semiconductor manufacturing stage of the supply chain would be beneficial.